976
FXUS66 KOTX 021806
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1106 AM PDT Thu May 2 2024

.SYNOPSIS...
Scattered afternoon showers will form over north Idaho and
northeast Washington today and again Friday. Afternoon
temperatures will climb into the 60s today, Friday and Saturday.
Sunday will be a chilly and rainy day as a slow moving low
pressure system brings widespread rain to the Inland Northwest.
Next week looks cooler than average and showery.

&&

.DISCUSSION...

Today through Friday Night...Expect spring showers again today in
parts of northern ID Panhandle and along the higher terrain along
the Canadian border. Stray lightning strikes possible, but
confidence is low in the likelihood of lightning strikes. Otherwise,
dry conditions will persist with partly cloudy skies and light
winds. Some showers might bring pea-sized hair and 30 mph wind
gusts. Temperatures will be a bit warmer than today, randing from
the low to mid 60s.

On Friday, frost won`t be a widespread in the morning, with lows in
the mid 30s to low 40s. Skies will be mostly be clear in the
morning, with increasing clouds from the west in the afternoon,
becoming overcast overnight. The threat of showers returns with
less coverage over northeastern Washington and the ID Panhandle
for Friday afternoon. The pressure gradient will tighten through
the afternoon as the next low begins to move closer to the coast,
leading to increasing winds in the Waterville Plateau and Okanogan
Valley with gusts of 30 to 40 mph. Prefrontal warming will
increase temperatures again slightly with highs in the mid 60s
with a few 70s possible near the LC Valley and the Columbia Basin.
Rain will move east over the Cascades overnight, marking the
start of a wetter and cooler weekend. /KM

Saturday and Sunday: Ensemble models are in good agreement of a
transition to wet and cooler conditions. Saturday will be the last
warm day with temps in the 60s, which is average for this time of
the year. Clouds will spread in through the day, which may hinder
temps a few degrees. Precipitation will begin to spread into the
region as a low pressure system begins to move into Oregon. This
will provide good upslope flow into the Cascades and enhance
precipitation. Rain will likely not reach the Idaho Panhandle
until the afternoon.

Sunday the low moves inland with precipitation taking over the
majority of the region. The exception would be parts of the lee of
the Cascades where westerly flow may shadow the area. There is
high uncertainty in the temperature forecast. NBM wants to go 50s
and 60s, where the large majority of other models want to go 40s
for eastern WA and north ID where they will see the heavier rain
amounts and 50s for the central WA valleys and lowlands. Have
trended temps down, but may still be too optimistic. Wouldn`t be
surprised if Spokane struggles to get into the mid 40s on Sunday.
Ensemble forecast is split 50/50 on if Spokane will make it to 45
degrees Sunday.

Monday through Thursday: Conditions remain unsettled with a
showers remaining in the forecast through the period as the
through exits and another moves in. Daytime temps will slowly warm
through the week. Low temps though look to bottom out Tuesday and
Wednesday mornings as clouds decrease and the potential for brief
radiational cooling. Monday and Tuesday there is a 15-20% chance
of thunderstorms in the afternoon as temperatures cool at 500 mb
and the next trough takes on a bit of a negative tilt. Winds will
be breezy out of the west or southwest Monday and Tuesday across
the Columbia Basin and into the Palouse and Spokane area. Gusts 20
to 30 mph is currently forecast. /Nisbet


&&

.AVIATION...
18Z TAFS: VFR conditions will prevail at the TAF sites today and
through Friday. Convective showers will develop over the
mountainous terrain of the Idaho Panhandle as well as northeast
and north central Washington mainly between 20-02z. Showers won`t
be heavy rain makers since the lower atmosphere is quite dry.
Light rain and virga that occurs around Sandpoint, Bonners Ferry,
Colville, Republic, Deer Park, Winthrop, and Kellogg may be
accompanied by gusty outflow winds. Gusts as high as 30 mph will
be possible as precipitation evaporates in the dry air leading to
chilly outflow gusts.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
There is a 20 percent chance of lightning and pea hail mainly over
the high terrain around Bonners Ferry, Sandpoint, and Colville. A
few lightning strikes will be possible between 20z-02z as well.
/GKoch

-----------------------

Confidence descriptors:
Low - Less than a 30 percent chance
Moderate - 30 to 70 percent chance
High - Greater than a 70 percent chance

For additional probabilistic information for NWS Spokane airports,
please refer to the Aviation Dashboard on our webpage:
https://www.weather.gov/otx/avndashboard

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        62  37  66  46  68  42 /  10  10   0   0  20  50
Coeur d`Alene  59  36  64  43  67  43 /  10  10   0   0  20  50
Pullman        58  35  63  46  65  40 /   0   0   0   0  30  70
Lewiston       65  40  71  47  70  47 /   0   0   0   0  30  80
Colville       63  34  65  41  68  43 /  20  20  20  10  20  40
Sandpoint      57  37  61  42  66  45 /  50  50  20   0  20  50
Kellogg        56  37  61  43  65  45 /  20  20  20   0  20  50
Moses Lake     67  37  71  52  67  45 /   0   0   0  20  60  60
Wenatchee      65  43  67  52  60  48 /   0   0   0  30  70  60
Omak           67  40  69  50  68  48 /  10  10   0  10  40  40

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&

$$